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Number Sequence Calculator

Identify an arithmetic or geometric sequence and find any term.

How it works Report a problem

Number Sequence

Detect arithmetic & geometric patterns, find terms

About the Number Sequence Calculator

Identify an arithmetic or geometric sequence and find any term.

How to use the Number Sequence Calculator

  1. Enter at least three terms in Number Sequence, separated by commas.
  2. Enter N to find the Nth term.
  3. Press Calculate.

Formula and method

Arithmetic: aₙ = a₁ + (n − 1) × d. Geometric: aₙ = a₁ × rⁿ⁻¹.

Worked example

For 2, 5, 8, 11, 14 the common difference is 3, so the 10th term is 2 + 9 × 3 = 29.

Tips

  • Check the difference between terms for arithmetic sequences and the ratio for geometric ones.
  • Some sequences (such as Fibonacci) follow other rules.

Frequently asked questions

What is a common difference?
The constant amount added to each term to get the next in an arithmetic sequence.